Obstetrics Flashcards
(43 cards)
Pregnancy has what effect on MAC? when does it return to normal?
decreased by 40%; ~three days after pregnancy
What are the treatments for HoTN during delivery?
phenylephrine/ephedrine, supp O2, L uterine displacement, IVF
Blockade of anterior nerve root fibers causes blockade of what? posterior?
anterior - efferent motor and autonomic outflow; posterior - somatic and visceral sensation
Why do obstetric patients desaturate so quickly?
at term, MV increases by 50% while at the same time FRC decreases by 20%
Why are obstetric patients usually anemic?
at term, blood volume increases by 1-1.5L while plasma volume increases by 45%
What components add to the increased cardiac output of obstetric patients? How much is cardiac output increased?
HR increases 15-20%; SV increases 30%; CO increases 40%
What factors contribute to GERD in obstetric patients?
decreased LE sphincter due to displacement of stomoch by uterus, elevated progesterone, hypersecretion of gastric acid
What is human chorionic somatomamotropin?
a hormone similar to growth hormone; it modifies the metabolic state of the mother to facilitate energy supply to the fetus
What noticeable changes does human chorionic somatomamotropin have on the obstetric patient?
relative insulin resistance (hyperglycemia); increases insulin levels; pancreatic beta cell hyperplasia; gestational diabetes
What causes decreased uterine blood flow?
systemic hypotension, aortocaval compression, uterine vasoconstriction (catecholamines, vasoactive drugs), contractions
What are the two parts of stage 1 labor?
early labor - cervix gradually effaces and dilates up to 3cm; active labor - cervix dilates more rapidly and contractions are longer, stronger and closer together
Where do patients generally feel pain during labor? which dermatomes are these?
stage 1 - (mostly visceral) lower abdomen, lumbosacral area, gluteal region, thighs (T10-L1)
stage 2 - onset of perineal pain (S2-4 [pudential nerve])
What is placenta accreta?
abnormally deep attachment of the placenta to the myometrium
Up to what sensory level does a patient need to be blocked for C-section?
T4
Pain relief during labor needs to be provided at what sensory level during each stage?
stage 1 - T10-L1; stage 2 - T10-S4
Why is it important to preload a patient with IVF? how much should be given?
blood loss, HoTN associated w/ sympathetic blockade; 500-1000cc crystalloid
PDPH is a greater risk in what neuraxial technique? why?
epidural; because a larger needle is used
What are the most important factors for spread/block height in neuraxial anesthesia?
spread (spinal) - baricity (CSF volume important for isobaric); block height (epidural) - injection site
What are the most important factors for duration in neuraxial anesthesia?
spinal - dose; epidural - choice of LA
What are the most important factors for onset in neuraxial anesthesia?
spinal - pKa; epidural - pKa
Which causes more profound HoTN, spinal or epidural?
spinal
How far do you advance the catheter once in the epidural space?
3-5cm
What is the treatment for PDPH?
IV hydration, 500mg caffiene, (epidural blood patch 12-20cc)
What are standard aspiration prophylaxis given and in what dose?
bicitra 30cc, metoclopramide 10mg, famotidine (Pepcid) 20mg
